Classify the reaction

Question

(NH4)2Cr2O7 ! N2 + 4 H2O + Cr2O3
as one or more of the following:
Z1) combination Z4) metathesis
Z2) decomposition Z5) displacement
Z3) redox
1. Z2 only
2. Z2 and Z5 only
3. Z2 and Z3 only
4. Z3 and Z5 only
5. Z1 and Z3 only

Answer 1

None of our tutors is expert in "ap." If this is a chemistry question, you should have indicated that so that a chemistry expert could help you.

Answer 2

I assume ! stands for an arrow. Arrows are written easily either --> or ==>.

The reaction shown is a decomposition. Also it is a redox reaction.